Device for reinforcing the edge of a fabric

ABSTRACT

The working means for reinforcing the borders of a fabric by a leno weave are situated close to the binding place in the internal space of shafts of healds. This reduces the requirement for compensation of differences of tension of the binding threads, the requirement for floor space, and also the mass of the operating mechanism.

United States Patent I Rlha et a1.

DEVICE FOR R'EINFORCING THE EDGE OF A FABRIC Inventors: lfetr Rl'ha; Stanislav Kovar; Jii'l' Cernocky, all of Vsetin, Czechoslovakia Zbrojovka Vsetin, narodni podnik, Vsetin, Czechoslovakia Filed: May 13, 1974 Appl. No.: 469,452

Assignee:

Foreign Application Priority Data [56] References Cited UNITED STATES PATENTS 649,920 5/1900 Ellis 139/54 1703587 3/1955 Allenson... 139/54 1176.725 4/1965 Sample 139/54 Primary E.\'aminerHenry S. .laudon [57] ABSTRACT The working means for reinforcing the borders of a fabric by a leno weave are situated close to the bind ing place in the internal space of shafts of healds. This reduces the requirement for compensation of differences of tension of the binding threads. the requirement for floor space. and also the mass of the operat- 4 Claims, 4 Drawing Figures May 14 1973 Czechoslovakia 3394-73 u.s. C1. 139/54 Int. Cl D03d 11/00 i g n m- Field of Search 139/48, 50, 54, 55, 122 S SHEET 3 0? 3 En /I14 MP m- DEVICE FOR REINFORCING THE EDGE OF A FABRIC BACKGROUND OF THE INVENTION This invention relates to an arrangement for reinforcing the border of a fabric by a leno weave, such arrangement providing improved compensation of the length of the binding threads; the arrangement is also suitable for high speed shuttleless weaving machines.

A number of different arrangements have been used for reinforcing the borders of a fabric on weaving machines, by means of such arrangements the individual weft threads being interlaced at the borders. The reinforcement of borders of the fabric by a leno weave has thereby been proved to be rather advantageous.

Prior arrangements for forming a similar leno weave have usually a winding disk on both sides of the weaving machine, beside the outer warp threads, the winding disk being driven from the driving means for the weaving machine, the axis of rotation of the winding disk being parallel with the weft thread introduced into the shed. Bobbins are provided on the winding disk, the binding threads being supplied from the bobbins and being guided over compensating and tensioning elements to two opposite guiding channels situated symmetrically with respect to the axis of rotation of the winding disk and therefrom to the binding place of the fabric. The winding disk rotates in front of the outer warp threads in the space behind the heald shafts. The distance between the guiding channels in the winding disk must correspond to the size of the open shed at the given place of the warp. The further the winding disk is situated from the binding place, the larger must be the distance between the guiding channels for the binding threads and the greater must be the compensation of the lengths of the binding threads for the open and closed shed. The winding disk rotates in the course of operation of the weaving machine generally at half the speed of the weaving machine, and the introduced weft thread is at the moment of the blow bound by an alternate crossing the turning around of both binding threads supplied from the bobbins which turn with the winding disk upon which they are mounted.

A drawback of this arrangement is that it needs a relatively large space at both sides of the warp of the weaving machine, and the width of such machine is thus increased; this also increases the required floor space of the weaving mill. Due to its size and construction the arrangement can be situated only behind the heald shafts which represents a larger distance between the winding disk and the binding place of the fabric. It is therefore necessary to choose a larger distance between the guiding channels in the winding disk in order that the opening of the binding threads may correspond to the opening of the warp threads of the shed. This requires an increase of the diameter of the winding disk and thus also an increase of its mass, and increases greatly the requirements for compensation of-lengths of the binding threads to provide their required uniform tension. These requirements increase greatly in high speed weaving machines.

SUMMARY OF THE INVENTION It is an object of this invention to provide an arrangement for reinforcing the borders of a fabric by a leno weave, wherein the winding disk with the guiding channels for the binding threads are as close as possible to the binding place of the fabric, thereby permitting a small distance between these guiding channels and thus reducing the requirements for equalizing the tension of both binding threads.

It is another object to provide an arrangement which does not increase unduly the floor space required by the weaving machine.

The arrangement according to a preferred embodiment of this invention is supported on a body which is adjustably arranged on a support fixed on the guiding means for heald shafts on the frame of the weaving machine. An arm is fixed to this body, said arm passing through the internal space of the heald shafts and the healds, for instance between the posts of the heald shafts and the healds, its extremity being spaced a distance corresponding to the minimum required working distance needed by the reed in its extreme rear posi tion. A bed for rotatably supporting the winding disk is provided on the end of this am. The winding disk has on its circumference a cogged pulley for receiving an indented belt or timing belt driving the winding disk from a countershaft; the rotating motion from such countershaft is transmitted via a bevel gear to a shaft driving via a gear a bobbin supporting disk having with the supply of binding threads on bobbins carried thereby. The binding threads are guided from the bobbins over a device for equalizing their tension and further to a common eyelet on the face of a distributing mandrel, being led by means ofthis eyelet to the weaving plane.

The distributing mandrel is fixed to the supporting disk and cooperates with the winding disk at a synchronous speed of rotation. The eyelet on the face of the distributing mandrel has an internal opening in the shape of a slot symmetrical with the axis of rotation of the distributing mandrel. The length of the slot is determined so that in case of the turning of the distributing mandrel through an angle of i.e., in case of a turning from a position parallel to the weft thread introduced to the shed to a position perpendicular thereto, such a change of distances between the binding place and the adjacent place of the slot is created that is corresponds to the difference of an equal length of the binding threads in case of a closed and open shed, measured in the weaving plane. A pivotable arm with an extension for separating one binding thread from the other is also supported on the distributing mandrel in front of the slot.

A main advantage of the arrangement according to this invention is that the winding disk with the guiding channels for the binding threads can be situated up to a minimum distance from the binding place of the fabric, quite close to the reed in its extreme rear position. The smallest possible distance of the quiding channels in the winding disk is achieved, thus reducing the difference of lengths of the binding threads between that at a closed and that at an open shed; this difference is furthermore fully compensated by the slot of the eyelet for both binding thread, said slot being symmetrical to the rotation axis of the distributing mandrel, so that no excessive tension of the binding threads is generated when the shed is opened. Another advantage is that the arrangement requires no large space on the weaving machine and is easily accessible so that it can be easily attended directly from the attendants station. The store of binding threads on the bobbins can be also easily checked. The arrangement can be also used for the DESCRIPTION OF THE DRAWINGS FIG. 1 with the cover of bobbins shown in section, the

view showing the store of binding threads and the device for equalizing and for adjustment of their tension; and

FIG. 3 and 4 illustrate diagramatically the principle of compensation of the lengths of the binding threads for a closed and open shed.

DESCRIPTION OF PREFERRED EMBODIMENT The arrangement on the left side of the weaving machine is supported by a body 1, which in turn is adjustably fixed by a strap 2 on a support 3, fixed to guiding means 4 and 5 for heald shafts 6 on the frame of the weaving machine.

An arm 7 is fixed to the body 1, with a winding disk 9 rotatably supported by a two-part bed on the end of the arm 7. A cogged pulley is provided on the circumference of the winding disk 9 for receiving a cogged or Timing belt 10 for driving the winding disk 9 from a countershaft 11 via a gear 12. The countershaft 11 is driven by a cogged belt 13 from the main drive of the weaving machine by a shaft 14 via gears 15 and 16. The gear 16 is fixed to the shaft 14 by a screw 17, with inserts 18 and 19 at both sides of the gear wheel 16 for preventing any lateral sliding of the cogged belt 13. The exact distance between the axis of the countershaft 11 and the driving shaft 14 is secured by a spacer 20 fixed to the body 1. The rotating motion is furthermore transmitted from the countershaft 11 by bevel gears 21 and 22 to a shaft 23 with a gear 24 engaging with a gear 25 fixed on the distributing mandrel 26 together with the bobbin supporting disk 27. Bobbins 29 and 30 with a store of binding threads 31 and 32 are supported on disk 27 symmetrically to the axis of rotation 28 of a distributing mandrel 26, the whole arrangement being covered by a transparent cover 33.

The binding threads 31 and 32 are guided from the bobbins 29 and 30 by a device for adjusting and equalizing their tension at both sides of the extension 34a of the pivotable arm 34 to the eyelet 35 on the face part of the distributing mandrel 26, and therefrom through guiding channels 36 and 37 in the winding disk 9 to the borders of the fabric for binding the weft thread 38 and to the binding place. The face part of the distributing mandrel 26 extends with its eyelet 35 up to the weaving plane 40 (see FIGS. 3 and 4).

In order to secure a perfect compensation of the binding threads 31 and 32 at a closed and open shed, the following condition must be filfilled (see FIGS. 3 and 4).

whereby the binding place 39 is considered to be stable. This condition is met, if the length of the slot of the eyelet 35 is determined as follows: m=s+2k=s+2(L-N)= m is the length of the slot of the eyelet 35 fixed on the face of the distributing mandrel 26.

s is the width of the slot of the eyelet 35,

k is the difference between the lengths of the binding threads 31 and 32 at an open shed and a closed shed measured in the weaving plane,

L M s/2 is the distance between the binding place 39 and the adjacent border of the slot of the eyelet 35 in a position of the slot parallel with the weft thread introduced into the shed,

M is the distance of the axis of rotation 28 of the distributing mandrel 26 from the binding place 39,

N is the distance between the binding place 39 and the adjacent border of the slot of the eyelet 35 in a position of the slot perpendicular to the weft thread introduced into the shed,

R is the distance between adjacent borders of openings of guiding channels 36 and 37 in the winding disk 9,

n is the distance of the rotation axis of the winding disk 9 from the adjacent border of the slot of the eyelet 35, perpendicular to the weft thread,

1,, 1 are sections of the length L with respect to the axis of rotation of the winding disk 9 at a closed shed,

n n are sections of binding threads 31 and 32 at an open shed whereby the sum of their projections in the weaving plane is equal to the distance N.

The arm 7, on the end 8 of which the winding disk 9 is rotatably supported, passes through the internal space between the heald shafts, for instance according to FIG. 2 between posts 41 of shafts of healds 6 and healds 42 and reaches up to a minimum operating distance from the reed 43 fixed to the slay 44 together with a weft introducing jet guide.

The same arrangement is used for reinforcing the border on the right side of the weaving machine; some of the elements, of course, have to be in a right hand alternative and, in addition, the countershaft 11 is on the right side of telescopic construction in order to be able to adjust the arrangement on the support 3 according to the required reed width of the fabric worked on the weaving machine. A part of the countershaft 11 is connected with a hollow part 46 of the shaft into which there is inserted the retractable part 47 of the shaft, on which a gear 48 for the drive of the winding disk 49 by a cogged belt 50 is fixed, whereby the rotating motion is also transmitted by bevel gears 51 to a shaft for turning the store of binding threads for reinforcing the border of the fabric. The retractable part 47 of the shaft is also hollow, with an expanding mandrel 53 passing through it, by means of which the end 47a of the retractable part 47 of the shaft is expanded when changing the reed width of the fabric. Nuts 54 secure the expanding mandrel 53 and thus also the retractable part 47 of the shaft in the hollow part 46.

By this arrangements on the left and right side of the weaving machine the operations on the right and left sides can be shifted in phase so that, for instance, the arrangement on the right side can bind the weft thread earlier than the arrangement on the left side; this is advantageous with air operated (jet) weaving machines.

The arrangement operates so that when the shaft 14 of the main drive is rotating the countershaft 11 rotates at the same speed, its rotating motion being transmitted to the winding disk 9 at half this rotating speed. The disk winds the binding threads 31 and 32 around each end of the weft thread 38 introduced into the shed in the same manner as in prior devices of this kind. The binding threads are supplied to the guiding channels 36 and 37 of the winding disk 9 from the distributing mandrel 26 which rotates at a speed synchronous with the winding disk 9 and distributes the binding threads 31 and 32 coming from bobbins 29 and 30 by way of a device for equalizing and adjusting the tensions of the binding threads 31 and 32.

The arrangement at the right side of the weaving machine can be adjusted according to the required reed width of the fabric by loosening both nuts 54, thus loosening the conical end of the expanding mandrel 53 by means of which the end 47a of the retractable part 47 of the shaft is expanded in the hollow part 46 of this shaft. The strap piece 55, by which the body 56 of the arrangement for reinforcing the right border of the fabric is fixed to the support is subsequently loosened and the whole arrangement is adjusted for the required width of the fabric, after which the respective parts are again fixed.

Although the invention is illustrated and described with reference to one preferred embodiment thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a preferred embodiment, but is capable of numerous modifications within the scope of the appended claims. What is claimed is:

1. In a weaving machine having a frame, guiding means for heald shafts and a reed having a front and rear extreme position, an arrangement for reinforcing by a leno weave a border of a fabric woven on said machine, said arrangement comprising a support fixed to the guiding means for the heald shafts, a main body for adjustably supporting the arrangement proper for reinforcing the borders of the fabric mounted on said support, an arm fixed to said body, the arm being disposed in the internal space of the heald shafts up to the reed in its rear extreme position, a winding disk, two guidung channels for binding threads provided on this winding disk symmetrically and oppositely with respect to its axis, a bed for rotatably supporting the winding disk provided on the end of said arm, the axis of rotation of the winding disk being substantially parallel with the weft introduced into the shed, a bobbin supporting disk rotatably supported on the main body, two bobbins with a store of binding threads rotatably supported by the bobbin supporting disk, a countershaft receiving its drive from the drive of the weaving machine, the axis of the countershaft being parallel with the axis of the winding disk, means for transmitting the rotating motion from the countershaft both to the winding disk and to the bobbin supporting disk, a distributing mandrel fixed to the center of the supporting disk, an eyelet provided on the face part of the extremity of the mandrel, the face part with the eyelet of the mandrel being situated in the weaving plane of the weaving machine, the distributing mandrel being driven at a speed which is synchronous with the rotating speed with the winding disk.

2. An arrangement as in claim 1, wherein the eyelet at the face part of the distributing mandrel has an internal opening in the shape of a slot which is symmetrical with respect to the axis of rotation of the distributing mandrel.

3. An arrangement as in claim 1, comprising a pivotable arm with an extension for separating one binding thread from the other provided in the distributing mandrel in front of the slot of the eyelet.

4. An arrangement as in claim 1, wherein the arm fixed to the main body is disposed between posts mounting the heald shafts and the healds. 

1. In a weaving machine having a frame, guiding means for heald shafts and a reed having a front and rear extreme position, an arrangement for reinforcing by a leno weave a border of a fabric woven on said machine, said arrangement comprising a support fixed to the guiding means for the heald shafts, a main body for adjustably supporting the arrangement proper for reinforcing the borders of the fabric mounted on said support, an arm fixed to said body, the arm being disposed in the internal space of the heald shafts up to the reed in its rear extreme position, a winding disk, two guidung channels for binding threads provided on this winding disk symmetrically and oppositely with respect to its axis, a bed for rotatably supporting the winding disk provided on the end of said arm, the axis of rotation of the winding disk being substantially parallel with the weft introduced into the shed, a bobbin supporting disk rotatably supported on the main body, two bobbins with a store of binding threads rotatably supported by the bobbin supporting disk, a countershaft receiving its drive from the drive of the weaving machine, the axis of the countershaft being parallel with the axis of the winding disk, means for transmitting the rotating motion from the countershaft both to the winding disk and to the bobbin supporting disk, a distributing mandrel fixed to the center of the supporting disk, an eyelet provided on the face part of the extremity of the mandrel, the face part with the eyelet of the mandrel being situated in the weaving plane of the weaving machine, the distributing mandrel being driven at a speed which is synchronous with the rotating speed with the winding disk.
 2. An arrangement as in claim 1, wherein the eyelet at the face part of the distributing mandrel has an internal opening in the shape of a slot which is symmetrical with respect to the axis of rotation of the distributing mandrel.
 3. An arrangement as in claim 1, comprising a pivotable arm with an extension for separating one binding thread from the other provided in the distributing mandrel in front of the slot of the eyelet.
 4. An arrangement as in claim 1, wherein the arm fixed to the main body is disposed between posts mounting the heald shafts and the healds. 